Does a neonate with a small patent foramen ovale (PFO) require a repeat echocardiogram?

Management of Small Patent Foramen Ovale in Neonates

A small patent foramen ovale (PFO) in a neonate does not require a repeat echocardiogram unless there are specific clinical indications suggesting complications or associated abnormalities.

Understanding PFO in Neonates

A patent foramen ovale is a common finding in neonates, representing a normal physiological remnant of fetal circulation. It consists of:

• A communication between the right and left atria in the interatrial septum 1
• Two components: the septum primum and septum secundum 1
• A normal finding that is present in approximately 25% of the adult population 2

Natural History of PFO in Neonates

The majority of PFOs close spontaneously:

• More than 95% of PFOs close spontaneously by 6 months of age 3
• Spontaneous closure is more likely with:
  • Earlier diagnosis 4
  • Smaller defect size 4
  • Younger age at diagnosis 4

Clinical Decision-Making Algorithm

No Follow-up Echocardiogram Needed If:

1. The PFO is small (<3mm)
2. The neonate is asymptomatic
3. There are no associated cardiac abnormalities
4. There are no clinical signs of hemodynamic compromise

Follow-up Echocardiogram IS Indicated If:

1. Clinical symptoms develop:

   • Cyanosis
   • Respiratory distress
   • Congestive heart failure
   • Abnormal arterial pulses 5

2. Concerning physical findings:

   • Loud or abnormal murmur
   • Other abnormal cardiac findings 5

3. Associated conditions:

   • Chromosomal abnormality
   • Major extracardiac abnormality with high incidence of cardiac involvement 5
   • Lack of expected improvement in cardiopulmonary status in premature infants 5

4. Imaging findings:

   • Cardiomegaly on chest radiograph
   • Abnormal ECG suggesting structural heart disease 5

5. PFO characteristics:

   • Restrictive PFO (diameter <2mm with Doppler velocity >120 cm/s) 6
   • Associated atrial septal aneurysm 1

Rationale for Recommendation

1. The ACC/AHA guidelines do not list isolated small PFO as an indication for follow-up echocardiography in neonates 5.

2. PFO is a normal finding in neonatal circulation with high rates of spontaneous closure:

   • 65.9% close spontaneously in neonates under 1 month 4
   • 66.7% close spontaneously in infants 1-12 months 4

3. Clinical significance:

   • Isolated small PFOs without symptoms do not typically cause hemodynamic compromise
   • PFOs become clinically relevant primarily when associated with other cardiac abnormalities or when they are restrictive 6

Important Caveats

1. Distinguish between a small PFO and other atrial septal defects:

   • A PFO is a potential space between septum primum and secundum
   • An ASD is a true defect in the atrial septum

2. Be aware that a restrictive PFO (diameter <2mm with high velocity flow) may be associated with pulmonary hypertension, but these cases often resolve spontaneously without intervention 6

3. Documentation in the medical record should include:

   • Size of the PFO
   • Direction and magnitude of shunting (if present)
   • Presence or absence of associated cardiac abnormalities

4. Parental education should include:

   • Reassurance about the benign nature of isolated small PFOs
   • Signs and symptoms that would warrant medical attention
   • Expected natural history of spontaneous closure

By following this approach, unnecessary follow-up echocardiograms can be avoided while ensuring appropriate monitoring for neonates with clinical indications that warrant further evaluation.